Question: Can vampires and werewolves be killed or injured by anything other than vampires and werewolves?
Answer: Sure. The problem is that these films portray vampires and werewolves as having super-human abilities, so it'd be significantly harder for a regular person to kill one. But nothing about the films seems to indicate it's overtly impossible.
Question: Is it common to be committed like Pat was to avoid a jail sentence? Is this up to the judge?
Answer: It's not exactly common, but yes, it would be up to the judge, and establishing that a person is a "clear and present danger to themselves or others" can result in involuntary commitment in Pennsylvania, where the film takes place. In this case, it would not be hard to argue that, "the person has inflicted or attempted to inflict serious bodily harm on another and that there is a reasonable probability that such conduct will be repeated" (50 PA. CONS. STAT. ANN. ยง 7301 (b) (1)), as he had just physically assaulted his wife's lover and she'd obtained a restraining order. His mental health problems would have been well-documented, so it would have been easy for a judge to order him to undergo psychiatric evaluation, which could (and, in the film, does) lead to extended involuntary commitment at the discretion of a mental health professional.
Question: Did one of the church ladies in the "Hit Me With Your Best Shot" scene, poop herself? The one with the floral shorts. Watch at the end when she is walking out of the church. (00:25:15)
Answer: The marks could be from when they were sliding across the pews.
Answer: 100% period! If you watch from the beginning of the scene, you'll see the stain slowly growing, also it's not on the side of her shorts, is in-between her legs, and eventually down the back.
Answer: Period shorts.
Question: Can someone please explain the photos in the yearbook? It seems like it was the gang in 1999, but they never posed for those photos in the first American Pie.
Chosen answer: They have been friends for a long time. They had plenty of time to take pictures. We only see them on screen for a few hours of their lives spread over a short while.
Question: How is it possible, given that Erik killed him in Phantom, that Piangi is a prominent character in Love Never Dies?
Chosen answer: I can't understand how you think Piangi is in Love Never Dies, let alone is a prominent character. Piangi is not a character in the original play or the 2012 version.
Answer: Aro also makes the argument that for the first time in our history humans pose a threat to our kind with their weapons that can destroy us. Theoretically any weapons that can tear apart and/or burn the vampires would work. So, yes, things other than vampires and werewolves can kill the vampires and werewolves.